We report on anomalous conductance in a resistively and capacitively shunted Josephson junction which is simultaneously driven by ac and dc currents. The dependence of the voltage across the junction on the frequency of the ac current shows windows of absolute negative conductance regimes, i.e. for a positive (negative) dc current, the voltage is negative (positive).
@article{arxiv.0705.2509,
title = {Frequency Windows of Absolute Negative Conductance in Josephson Junctions},
author = {L. Machura and M. Kostur and P. Talkner and P. Hanggi and J. Luczka},
journal= {arXiv preprint arXiv:0705.2509},
year = {2009}
}